Sunday, May 19, 2013

Replicating the Autochrome process

Recently, a friend asked me if I knew of any simple way of achieving the look of the autochrome color process with digital images. I was intrigued enough to do a bit of research and give it a try. I had an original autochrome glass transparency so I scanned it to use as my sample control image.

This is an original Autochrome plate which I scanned in to use as a control sample for imitating the process. Click here to download a hi res version of this file.

Autochrome was the first color process. It was invented by the Lumière brothers in France and introduced in 1907. It was an additive process consisting of three color layers each dyed a different color -- a blue-violet layer, red-orange layer, and green layer -- and resulted in a glass plate transparency. The exaggerated grain structure was a result of its being composed of tiny grains of potato starch. The muted, grainy look of Autochrome echoed the contemporary artistic look of Impressionist and Pointillist paintings. To me, the results also bear a strong similarity to the look of the Fresson photographic printing process.

I experimented with a few Photoshop techniques to achieve the look and feel of Autochrome, but settled on using the one that comes included as part of Alien Skin's Exposure 4 Photoshop plugin. I found it necessary to do some minor tweaking to the results to come closer to the grainy look, and then muted the images to fade them a bit.

In addition to using the plug-in I also added a color layer in OVERLAY mode, as described below, and added some noise to a level of 5-7. I found that the noise broke up the pattern of the grain a bit, added some more color to it, and also lowered the contrast. For some of the images I found it necessary to mute the colors even more by applying a Vibrance adjustment layer in Photoshop.

A full effect of the process requires seeing the images at full size so I included high res downloads with each file. Click on the caption links below the photos to download them.

I found the Autochrome grain structure difficult to mimic and modified the default Exposure 4 settings as illustrated above.

To provide a faded color cast and lower contrast similar to what I noticed in Autochrome images I added a color layer over the above image , and changed the mode of this layer to OVERLAY. I then decreased its opacity until it look right. For the tone of the color layer I chose a dominant color in my image and selected it using the color picker in Photoshop.

1 comment
:

Thanks for sharing this, I hadn't heard of that plugin before. Your original autochrome is so lovely and the digital ones as well. It's good to see people working with Autochrome. (In that vein, I created an app that makes regular photos look more like Autochromes, and it's free on the App Store)